TY - JOUR
T1 - A 96-well plate assay for high-throughput analysis of holocarboxylase synthetase activity
AU - Rios-Avila, Luisa
AU - Prince, Sara A.
AU - Wijeratne, Subhashinee S K
AU - Zempleni, Janos
N1 - Funding Information:
This work is a contribution of the University of Nebraska Agricultural Research Division, supported in part by funds provided through the Hatch Act. Additional support was provided by NIH grants DK063945 , DK077816 and ES015206 , USDA grant 2006-35200-17138 , and by NSF grant EPS- 0701892 .
PY - 2011/4/11
Y1 - 2011/4/11
N2 - Background: Holocarboxylase synthetase (HCS) catalyzes the covalent binding of biotin to both carboxylases and histones. Biotinylated carboxylases and biotinylated histones play crucial roles in the metabolism of fatty acids, amino acids, and glucose, and in gene regulation and genome stability, respectively. HCS null mammals are not viable whereas HCS deficiency is linked to developmental delays in humans and phenotypes such as short life span and low stress resistance in Drosophila. Methods: HCS-dependent biotinylation of the polypeptide p67 was detected and quantified in a 96-well plate format using IRDye-streptavidin and infrared spectroscopy. Results: Biotinylation of p67 by recombinant HCS (rHCS) and HCS from human cell extracts depended on time, temperature, and substrate concentration, all consistent with enzyme catalysis rather than non-enzymatic biotinylation. The Michaelis-Menten constant of rHCS for p67 was 4.1 ± 1.5 μmol/l. The minimal concentration of rHCS that can be detected by this assay is less than 1.08. nmol/l. Jurkat cells contained 0.14 ± 0.02. U of HCS activity [μmol of biotinylated p67 formed/(nmol/l HCS. h)] in 400 μg of total protein. Conclusions: We developed a 96-well plate assay for high-throughput analysis of HCS activity in biological samples and studies of synthetic and naturally occurring HCS inhibitors.
AB - Background: Holocarboxylase synthetase (HCS) catalyzes the covalent binding of biotin to both carboxylases and histones. Biotinylated carboxylases and biotinylated histones play crucial roles in the metabolism of fatty acids, amino acids, and glucose, and in gene regulation and genome stability, respectively. HCS null mammals are not viable whereas HCS deficiency is linked to developmental delays in humans and phenotypes such as short life span and low stress resistance in Drosophila. Methods: HCS-dependent biotinylation of the polypeptide p67 was detected and quantified in a 96-well plate format using IRDye-streptavidin and infrared spectroscopy. Results: Biotinylation of p67 by recombinant HCS (rHCS) and HCS from human cell extracts depended on time, temperature, and substrate concentration, all consistent with enzyme catalysis rather than non-enzymatic biotinylation. The Michaelis-Menten constant of rHCS for p67 was 4.1 ± 1.5 μmol/l. The minimal concentration of rHCS that can be detected by this assay is less than 1.08. nmol/l. Jurkat cells contained 0.14 ± 0.02. U of HCS activity [μmol of biotinylated p67 formed/(nmol/l HCS. h)] in 400 μg of total protein. Conclusions: We developed a 96-well plate assay for high-throughput analysis of HCS activity in biological samples and studies of synthetic and naturally occurring HCS inhibitors.
KW - Assay
KW - Biotin
KW - Holocarboxylase synthetase
KW - Human
KW - Recombinant
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U2 - 10.1016/j.cca.2010.12.031
DO - 10.1016/j.cca.2010.12.031
M3 - Article
C2 - 21195703
AN - SCOPUS:79951723176
SN - 0009-8981
VL - 412
SP - 735
EP - 739
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
IS - 9-10
ER -